In a Digital Television Broadcasting system involving the Orthogonal Frequency-Division Multiplexing (OFDM) technology, co-channel interferences from analog television (TV) signals and in-band channel interferences need to be detected and removed. An analog TV signal is composed of continuous waves, e.g., image carriers and sound carriers, each having a fixed frequency. When the fixed frequency is exactly the same as a frequency of a sub-carrier in an OFDM system, information carried by the sub-carrier shall be damaged.
In a Digital Video Broadcasting over Terrestrial 2 (DVB-T2) system, a data stream transmitted in the form of frames has a P1 symbol at its start position, and the P1 symbol comprises information of a transmitting end, e.g., the information of a Fast Fourier Transform (FFT) mode applied to a data modulation, or information indicating whether a digital communication system is a single-input-single-output (SISO) or a multiple-input-signal-output mode (MISO).
Therefore, an apparatus and a method capable of accurately detecting interferences are in need.